Manufacture of ammonia.



E. ORE MANUFACTURE OF AMMONIA. APPLICATION HLED OCT. 12, 191?.

Patented May 14, 1918 2 SHEETS-SHEET 1.

,1 rraRA/E);

E. ORE.

MANUFACTURE OF AMMONIA. APPUCATION HLED ocr. 12, 1911.

2 SHEETS-SHEET 2.

.Ernesi' o 'e' Arr-0R: r.

Patentd May 14,1918.

UNITED STATES PATENT OFFICE.

Specification of Letters Patent.

Patented May 14, 1918.

Application flied October 18, 1917. Serial No. 198,818.

To all whom it may concern:

Be it known that I, Ennns'r Oaii, a citizen of the Republic of France, and resident at Caen, (post-oilice address 11 Rue de la Masse, France, have invented a new and useful anufacture of Ammonia, which imroved process is fully set forth in the folowing specification.

During the carbonization of coal in a closed vessel, ammonia is generated, either free ,or in combination; which ammonia dis- 4 tils over at the same time as the coal gas. Steam and other vapors also distil over and are collected and condensed, the steam dissolving art of the ammonia products, the rest of w ich is collected by washing the gas in clear water. The ammonia recovered in these two ways forms the ammonia liquor proper. The ammonia liquor is then separated, and is finally distilled so as to su ply volatile ammonia which as it escapes mm the distilling apparatus, is collected in a given absorbent, such as distilled water or sulfuric acid, accordin as it is desired to obtain, as the final product, ammonia water or ammonium sulfate. Generally it is the sulfate that is manufactured in this way.

This is an old method of recovering ammonia and is still almost universally used. As in its first o oration or step the process does not give a nalfroduct, but yiel s only an intermediate pro uct, ammonia liquor, it is known as an indirect process of recovery or of conversion to ammonium sulfate, owing to the fact that the final product is generally the sulfate; It would be a great improvement of the intermediate use of water could be dispensed with, and the gas containing the whole of the ammonia in volatile state could be-sent direct into a selected absorbent, such as sulfuric acid. a

This would avoid washing in water, and consequently avoid the use of ammonia washers and the apparatus for distilling ammonia water. The result would be a considerable reduction in the cost of installation, an economy of space and more particularly a considerable reduction in the cost of labor, maintenance and fuel; The pro suggested for the urpose of avoiding washing in water are own as recesses of direct and semi-direct conversion into sulfate. The former have hitherto given only costly industrial results.

The only p which have been ractioally adopted are those called semiprocesses. In these processes, condensed ammonia liquor containing more particularly fixed ammonia, is collected and treated as 111 the old indirect process. Only the volatile ammonia contained in the gas leaving the condensers is absorbed in sulfuric ac1d by washin These processes substantially replace t e old process of washing.

with water.

This invention relates to a process for the complete direct conversion into sulfate, and also for they direct complete recovery of the ammonia generated by carbonization in a closed vessel of coal or of other materials such as wood, lignite or peat based on the exhaustion of ammonia waters of condensation within their condenser; the exhaustion being effected out of contact with the gas forming the vehicle for the ammonia.

The process chiefly consists in adding a suitable material, such as lime or sodium carbonate, to the waters of condensation before they leave the condensin a paratus, but out of the circuittraversed y the gas.

The quantities of lime or sodium carbonate are determined in the usual manner in accordance with the quantities of fixed am monia contained in the waters of condensation, and the fixed ammonia is converted into volatile ammonia within the apparatus in which these waters are condensed, the said apparatus being worked at such a temperature that the condensed waters can escape, can be exhausted, and still have too high a temperature to absorb volatile ammonia.

'It is generally admitted that water does not absorb free ammonia above 70 C. On the other hand, ammonium carbonate escapes from its aqueous solutions at 78 to 80 0.; but as in this case an ammonia solution of complex and variable composition is to be dealt with, obviously the temperature suitable for the treatment in question, must be determined experimentally in accordance with the composition of the ammonia liquor.

It is obvious that the small quantity of ammonia iquor which may escape condencation in t e decomposing apparatus, but is condensed farther on in the subsequent apparatus, is to be returned to the said decomposing apparatus.

Having thus discharged the waters of condensation completely exhausted, and having separated the whole of the ammonia in the gaseous current in volatile form, it is merely tar contained in the necessary to complete, by one of the numerous existing or analogous means, the elimination of the last traces of tar contained in the gas, and to recover the ammonia, the whole of which is now contained in the gas in a volatile state, b causing the said gas to bubble either in en furic acid, if ammonium suifate is to be obtained, or in some other suitable absorbent.

The process is particularly applicable to the manufacture of ammonium sulfate, but it can also be used for the manufacture of any other compound that can be carried out in a similar manner by the use of some other absorbent than sulfuric acid.

The invention includes the use for the decomposition of fixed ammonia, of lime, milk of lime, sodium carbonate or other similar material in any form, such as powder, or fragments, in aqueous solution or otherwise.

The process can also be used for the recovery of ammonia obtained not only from coal, but also from any other organic matter which is treated by distillation or carbonization in a closed vessel, br so as to su ply under similar conditions a quantity 0 recoverable ammonia.

The process can be carried out in any kind of apparatus in which carbonization or distillation or a similar treatment takes place, such as coke ovens, gas retorts or gas gencraters.

More pin'ticulnrly in the ease of the dis tillafion of coal in Coke furnaces or gas retorts, the process can he applied, whatever be the method employed for roni'lensing the as generated, whether (lib. cinulensn ion o tar (also called deterring ol' nus) takes lllit't at a moderate u'nmrrutuir. for irr-tun-w not exceeding 40 i.. or n .1 high i llii l more in the neighborhood 0? l 'l'he accompany Lug; "hum-Eng: :-lli)\\ by way of exunudc an appurntiu f r ilw direct total conversion of :u'numuia lulu ammonium sul fate with (,lt.l't1lllll;-, 2' Hi the gas at :2 moderate temperature.

The gas is admitted through pipe "H at tlulcft hand side of the apparatus directly from the hydraulic main at. a temperature sufiiciently high to avoid any prclimiiuiry con densation of Water or any dcpo it of 11m monium salts. To that end. it n essary. the hydraulic main and the piping can lurow cred with heat insulating material. llie gas enters at the bottom of a olumn I of large diameter having a fairlv deep base and disk or plates provided with cups and overflows similar to those of distilling columns, and rises through the disks ofthc said column, which latter constitutes a condenser. Durhag-its ascent, the gas cools somewhat, and deposits or. the disks condensed ammonia waters and tar which liquids descend. from one disk to another. The condensed waters in which the gas splutters or bubbles at high temperat re, cannot retain volatile ammonia, but disso ve fixed salts of ammonia. At the bottom of the column the condensed waters and the tar se arate by gravity. The tar is discharged see the left hand side in the figure) through pipe 31 to a suitable tank or other receiver, not shown. The water of condensation escapes through Pl e 21 as shown on the right hand si e o t r figure, and passes to a decomposin column 2 char ed with lime, which may of any desire type. In this column, the ammonia water is mixed with milk of lime fed in the usual manner, and the fixed ammonia salts are decomposed; their acid being fixed by the lime, and the ammonia released assing through ipe 22 to the base of the co umn 1, where it ccorhes mixed with the ascending current of gas. At the bottom of the column 2 the s ent milk of lime is discharged with the ex austed ammonia waters. It is advisable to use two lime columns which are utilized alternately, in order to facilitate the cleaning frequent y required in this kind of apparatus.

he as, after having passed from bottom to top t rough the column 1, passes into condensers 3 and 4, of suflicient number for erfect deterring, the condensers 3 being of the surface type. These condensers 3 and 4 are on a higher level than the column 1, so that the condensates formed therein, return automatically by gravity through pipes 23 and 24 to the disks of the column 1. The said condensates. tar and ammonia water, thus descend in the column 1 and behave as has been seen, in the same way as the condensates formed in the column itself.

After escaping from the condensers 4 at a moderate temperature, the gas completely deprived of tar and containing the whole oi the ammonia in volatile form. is drawn in by a suitable exhauster or fan 5 and forced by the same ap aratus into a sulfuric acid saturator 6 in w ich the formation of ammonium sulfate takes place. The as escapes from the saturator complete deprivml of ammonia and passes into a separator 7 in which it leaves the drops of acid that it may have carried away. Thereupon it is cooler] and dried in a condenser 8 (or in several if necessary) and becomes suitable for any subsequent use.

The sulfate formed in the saturator, is withdrawn by means of an ejector and sent to a centrifugal drier 9 whence it falls drv and neutral on a conveyor band which oorivoys it to the store. The mother liquor obfumed by centrifuging. is discharged into a tank 10 whence it is sent back to the saturatnr by ordinary means. The saturator is of course provided with the necessary pipmp: for the reception of the said mother liquor and of sulfuric acid.

mean? The installation effects therefore direct conversion into annnonlum salts, the whole taking place in the denslng apparatus.

t is obvious that the process is applicable w ion the condensation of tar takes place at 'emperature, for instance at about understood without 1 accompanied 1me column of the ty c 2. This a as d escribed in e e gas has been the dischar he column 1 become useless. It is merely adas to pass, after the ephlegmator with a surface cooled by a water current,

regulated so as t tain a suitable temperature, in order gas may tain the whole of the ammonia in a volatile state. his gas can then be drawn in and forced into a saturator, and the will continue as in the receding which can hot gas generated by carbonization of organic material to a partial COOIIIIg, thereby removin therefrom the heavy ta ents an the ammonia hquors by liberating ammonia, an the ecomposed liquors free rom ammonia at a temperature above that permitting the absorption of the ammonia.

2. In the process of manufacturm monla, subjecting an ascending hot gas generated by carbonization of organic material to a partial removin therefrom the h ents an t scribing witnesses. V

ERNEST ORE. Witnesses Emu; Lnnm, CHAs. P. PRESBLII. 

